


thriller (under the moonlight)

by orphan_account



Category: Adventure Time
Genre: F/M, Finn is 14, marceline is like a thousand and looks 19 so i tagged as underage
Language: English
Status: Completed
Published: 2018-07-17
Updated: 2018-07-17
Packaged: 2019-06-11 23:05:37
Rating: Teen And Up Audiences
Warnings: Underage
Chapters: 1
Words: 1,411
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15326379
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: "Marceline!" He panted, daring to glance back. "This better not be a dumb prank-"And that was when he was tackled.Finn found himself laying down in the grass, a heavy weight on top of him and snarling ringing in his ears, when it started to rain.





	thriller (under the moonlight)

**Author's Note:**

> i've had the biggest urge to write something like this for ages haha and i finally gave in and i'm so sorry ;u; this isn't anything near explicit, but it's definitely somewhere in the middle of chaste and saucy, so here's your warning for that!

Finn hit the ground running.

Little was going on in his head, sans the desire to get away run run run don't fight-

He has no idea what happened, what caused this. All Finn is clear on is that he walked into Marceline's house, waving happily in greeting, and then....then-

Marceline's growling resonated through the damp, darkening forest. Finn drew in a panicked breath and sped up as best he could. She wasn't transformed. Besides the elongated fangs and claws, he'd never have noticed something was off if she hadn't attempted decapitating him the second he walked inside.

He didn't know what sorta crazy vampire and/or demon thing this was, but it was scary. Just get away. Don't fight. _You can't hurt your friend, Finn! Heroes don't do that!_

The woods around the two of them were deathly quiet. The constant growling and Finn's panicked breathing were the only things breaking the silence. 

A clawed hand latched onto his shoulder, and he squeaked, narrowly ducking out of the hold before she got a good enough grip on him. Considering the roar, that didn't make her too happy.

"Marceline!" He panted, daring to glance back. "This better not be a dumb prank-"

And that was when he was tackled.

Finn found himself laying face-down in the grass, a heavy weight on top of him and snarling ringing in his ears, when it started to rain.

He lashed out blindly with his arm, managing to catch her in the face, and barely had time to turn over before he was pushed backward. His back and head hit the ground, so hard he was momentarily stunned. It was enough for her to get both of his arms pinned above his head, growling coming inches from his face.

He wriggled uselessly, eyes squeezed shut. It's okay. It's okay! Just wait for the chance to escape, and it'll be fine! Wouldn't it?

The growling abruptly stopped. Her rough breaths hit his face before she leaned closer, inhaling near the side of his neck. He felt his hat being tugged off, probably for an easier shot at his fragile throat. He curled in on himself, knowing a killing blow was coming any second now, it had to be. Her claws dug painfully into his wrists as Finn tried to focus on calming himself down.

Breathe in. Breathe out. Breathe in. Breathe ou-

Something slick and warm slid up his jugular.

Finn gasped, eyes flying open. Was...

Was she _licking_ him? Was this something vampires did before they went in for the bite?

He tried to turn away, but her growl stopped him, and he stilled obediently. She almost seemed pleased, going right back to lapping at his neck like it was candy. Finn knew he was blushing, felt the heat in his ears and face, and he swallowed dryly.

Vampire meal-prep or not, it still felt weird!

He blew a strand of blonde hair out of his face, slowing his breathing down. Just endure it. She had to be done soon. This wasn't so bad. At least she wasn't hurting him. Maybe Finn would get lucky and she'd snap out of whatever this was before getting to the biting part.

A fang scraped against the underside of his jaw, not anywhere hard enough to break skin, but it was enough to make him whimper. Marceline stilled, pulling back far enough to stare at him. Her pupils were huge. 

The hero wasn't sure what to do, knew he had to still be blushing, and settled on looking up at her. He had to look so lame right now, helpless and red-faced. For the first time, he hoped Marceline wouldn't remember this. She'd never let him live it down. 

A rumble started up, deep in her throat and just loud enough for him to hear it over the rain. It didn't sound like much like a growl, and she didn't appear angry...

All at once, she was burrowed into the curve of his throat again. Finn could feel her inhaling against his skin, growling gaining volume. 

_You can do this you can do this you can do this--_

Her grip on his hands loosened. For a mere second, he had hope.

Claws fisted into his collar and ripped apart it with no hesitation. His shirt dangled somewhere off his shoulder and left his collarbones, everything fragile, exposed. 

"Eeep!" Finn squeaked, hands automatically rising to cover himself. Marceline had them both pinned again within seconds, eyes flashing a warning down at him. 

_I can't do this I can't do this I can't do this--_

She was nosing along his shoulder now, her warm breaths hitting skin chilled with rain, and his face felt like it was on _fire_ , and he wasn't even sure why. 

Something warm was pressed against his jugular, and he didn't even want to comprehend that it was her tongue. Think, Finn. Think!

What would Jake do in this situation? Scream. Cry. Probably use his stretching powers to escape.

Screaming would probably make her mad, Finn doubted crying would do anything, and he didn't have stretching powers. There ends all Finn's ideas. 

He yelped when the full weight of Marceline suddenly slumped against him. Face buried in Finn's collarbone, legs on either side of him, just...laying on top of him. He vaguely realized his hands were free.

"M...Marcy?" He called weakly, tilting his chin down. No reply. Her breathing was even and slow and would be almost comforting if not for, y'know, everything else.

Wait. 

Was she...

"Are you asleep?!" He hissed. "Really?"

Vampire friend randomly goes crazy and attempts to murder you (instead ends up mostly slobbering on you) and then falls asleep, right on top of your shivering body. Finn's life was gonked up. 

He would be more indignant if he didn't realize that this meant he probably wasn't dying anymore. At least not not if he could escape...

Finn wiggled. She didn't stir.

Holding his breath, a shaky hand raised, moving to her shoulder to push her off him and hopefully run for it. He'd barely begun to push before a familiar growl arose, cold arms wrapping back around him and holding him so tightly it hurt, a leg digging into his hip.

"Okay, okay!" He whispered, voice high with fear. "No running, got it!"

And so he stayed. The rain let up soon after, so that was something. Now he was only slightly wet, uncomfortably cold, and scared, instead of _soaking_ wet, uncomfortably cold, and scared. 

Finn hadn't realized he'd even fallen asleep until he was woken up by a groan that wasn't from him.

Eyes cracking open, his half awake-brain hadn't expected Marceline's face, inches from his own, to be the first thing he saw. He screamed, scooting backward. "Marceline! I'm not- You're-"

"Dude, calm down." Marceline mumbled, sitting up to stretch, arms raising high above her head. "It's too early for that."

"B-But-" Finn sputtered, following her lead and sitting up. His shirt was hanging off him, the collar ripped to shreds. "You-"

"Woooah." She says, and Finn sees her looking at his shirt, whistling lowly. Her eyes trace his collarbone after, and he doesn't notice. "What happened last night?"

"You...you don't know." He says slowly.

"Nah. I mean, I know I went outta control." She shrugs. "I have certain times when it all just comes outta me, y'know? Being a demon and a vampire, having to control all that junk, it gets a little...messy after hours."

Messy. He gets a sudden flash of warmth on top of him, slickness trailing the curve of his throat. _Messy._

"Oh." Is all he's able to say, ears burning. 

"Yeah. Shoulda warned ya not to visit after midnight." Marceline rubbed at the back of her neck, looking nearly apologetic. She was back to looking at his shirt. "So...what'd we get up to?"

Finn's mind shatters. "Huh?"

Marceline laughs at his dumbstruck expression, legs crossing as she relaxed against the stump of a tree. "I may not remember anything, but I know I get a little violent. Did we wrestle or something? Or did you just run away 'till I caught you, little hero?" She teased, but Finn could barely hear it past the ringing in his ears.

Oh.

Finn kept his eyes firmly on the ground, biting the inside of his cheek until it hurt. His face could cause a forest fire right now. 

"...Something like that."

**Author's Note:**

> i just caught up with AT completely yesterday and i just love finn so much!!!! i don't even ship this normally, love their friendship in canon, but something about it in this context just appeals to me and i'm so so sorry 
> 
> i imagine being a vamp AND demon has gotta wear down on your self control sometimes, and maybe it can overwhelm ya. sorta like a "werewolf under the full moon" deal lol, don't look too much into the way this works tbh i just wanted to write finn being chased and slobbered on 
> 
> i'm sure not many people are into this pair, much less like this, but if anyone likes this then thank you so much!


End file.
